Al-Mu'tasim

al-Mu'tasim (794-842) was the Caliph of the Abbasid Caliphate from 833 to 842, succeeding al-Ma'mun and preceding al-Wathiq.

Biography
al-Mu'tasim was born in 794 to Harun al-Rashid. He succeeded his brother al-Ma'mun as caliph in 833, and during his reign, he introduced ghulams (Turkish slave soldiers) to his military. He established a new capital at Samarra, and for most of his reign, he fought the Khurramites and the Tabaristani Mazyar. His worst enemy was the Byzantine Empire, and he led the sack of Amorium in 838. He died in 842, and he was succeeded by al-Wathiq.